In an anchor device, a communication hole in which a webbing pass-through portion and a pin insertion portion communicate with each other is provided at a plate, a webbing passed through the webbing pass-through portion is coupled to the plate, and a mounting pin is inserted into the pin insertion portion. Here, a narrowing portion of the plate narrows the width of communication between the webbing pass-through portion and the pin insertion portion. For this reason, the mounting pin can be inhibited from contacting the webbing when the mounting pin is inserted into the pin insertion portion.